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Finding the Fourth Proportional to 990.05, 1,366.34 and 570.42

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Solution

The fourth proportional to 990.05, 1,366.34 and 570.42 is: 787.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    990.05 : 1,366.34 = 570.42 : x
  2. Step 2: Convert to fraction form
    990.05/1,366.34 = 570.42/x
  3. Step 3: Cross multiply
    990.05x = 1,366.34 × 570.42
  4. Step 4: Simplify right side
    990.05x = 779,384.81
  5. Step 5: Solve for x
    x = 779,384.81/990.05
  6. Step 6: Final answer
    x = 787.22

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.